Railway signaling apparatus



Jan. 9, 1940. P. H. CRAGO 2,186,800

RAILWAY SIGNALING APPARATUS Filed Nov. 15, 1938 VENTOR Pau 01 090. BY

HIS ATTORNEY atented Jan. 9, 1940 PATENT v OFFlCE RAILWAY SIGNALING APPARATUS Paul H. Crago, Wilkinsburg, Pa., assignor to The Union Switch 8;- Signal Company, Swissvale, Pa.,,a corporation of Pennsylvania Application November 15, 1938, Serial No. 240,525

Claims.

My invention relates to railway signaling apparatus, and has for an object the provision of novel and improved means for transferring the operation of a signal from its normal source of current to a stand-by source in the event that the voltage of the normal source drops below the operating voltage of such signal.

I shall describe one form of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

' The accompanying drawing is a diagrammatic view showing a preferred form of apparatus embodying my invention when applied to the control of a highway crossing signal.

Referring to the drawing, the reference characters I and la designate the trafiic rails of a stretch of railway track X over which traflic moves in both directions, and which is intersected at grade by a highway H. A'highway crossing signal S is located at the intersection. Signal S may be any one of the'several forms of highway crossing signals, and is illustrated in the drawing by a symbol employed in the art to represent a signal of the type having an os-' cillating signal arm. I

Signal S is arranged to be controlled by traffic operating over the stretch of railway track;

As herein shown, rails I and. la are divided by means of theusual insulated rail joints 2 into track sections DE and E-F, extending in 1} opposite directions from the intersection. The track sections DE and E-F are provided with track circuits, each circuit comprising a suitable source of current, such as track battery 3, connected across the track rails at one end of ,2" the section, and one winding of an interlocking relay XR connectedacross the rails at the other end, winding WI being interposed in the circuit for section DE and winding W2 being interposed in the circuitfor section E-Fl Winding WI is provided with back contact 4, closed only in the released. position of the armature associated withwinding WI, and'with front flagman contacts 5 and 6, closed in the locked po- .sition as well as the energized position of the armature. with back contact 1 and front flagman contacts 8 and 9.,

Signal S, as shown, is provided with an operat- 50 ing mechanism designated as a whole by the reference character M. The operating mechanism of signal S may take different forms and, as here shown, is of the type described and covered by United States LettersPatent No. 1,498,

u 157, granted on June 1'7, 1924 to C. W. Dunham Similarly, winding W2 is provided (Cl. 246-130) for Highway crossing signal. As herein shown;

the signal mechanism comprises in its essential elements a signal arm Ill carryinga shield Ilia and a lamp- L, and pivotally pinned for rotation about a pin II secured to a mounting member (not shown). The arm It is connected by means of a member I2 with a pivotally arranged armature I3. The armature I3 is adapted to be attracted alternately to one magnet It or the other magnet E5 of a normally deenergized operating 10 element, and is arranged to close contact IG-Il when attracted to magnet I 4, and to close contact I'I-I8 when attracted to magnet I5. The armature I3 and arm Ill are normally latched to the position shown by means of a normally m energized latching means herein shown as an electromagnet I9 adapted to attract an armature 2B, which is pivotally mounted on a pin 2i. The armature 20 is provided on its extreme outer end with a projecting pawl 22, which is adapted to coact with the lower end of armature I3. When magnet I9 is energized, armature 2?] is attracted to a position wherein pawl 22 lies in the path of movement of armature I3 with the result that armature I3 and arm Illare latched in the position shown'in the drawing. In the latched position of the arm- Ill, thearm and the shield Hid carried thereby are adapted, in accord'ance with the usual'practice, to be obscured behind obstructing plates (not shown). When the magnet IB is deenergizedarmature it is released 3 and swings in a'clockwise direction to release armature I3 from its latched position. The armature 2ll of the latching means also controls a circuit controller comprising twdcontact members 23 and 26, which are biasedinto mutual Q engagement. Control of the contact 23-24 is established by providing armature Ell with a slot 2Ia through which passes the mounting pin 2| so that armature 20 iscapable of longitudinal as well as swinging movement. lhe armature ilil carries a knob 22a of insulating material which is adapted at times to engage contact 2% to open I the contact 23-24. v "The operation of the signal is as follows: Normally, when magnet I9 is energized, armature is engaged by pawl 22 of armature 2i],

sfi'thatfarmature I3 is retained in its latched position, and armature 2B is operated to its ex treme right-hand position, as shown in thedrawing, so that contact 23-24 is open. When, however, magnet I9 is deenergized and permit/sar-v mature 20, to swing in a clockwise direction, ar-' mature I3 is unlatched, and contact 23-24 is closed by virtue of its bias to complete the con- 5g;

trol circuit for magnet I5 of the operating means. The unlatching of armature I3 permits the arm I0 to swing downwardly, and the energization of magnet I5 attracts armature I3 to swing arm ID upwardly to the right, as viewed in the drawing. The swinging of armature I3 to the right opens contact i6I'l interposed in the control circuit for magnet I5, and closes contact I'I-I8 interposed in the control circuit for magnet I4. The deenergization of magnet I5 permits armature I3 and arm II] to swing downwardly, and the energization of magnet I4 attracts the armature and arm to the left, the movement of the armature I3 reclosing contact I6I'I and reopening contact I'II8. This cycle of operation is periodically repeated as long as the apparatus is controlled to its operating condition, the parts usually being so proportioned that an operating cycle is completed substantially every two seconds or thirty times per minute, and usually being further proportioned so that a predetermined operating voltage is necessary to effect proper operation, and latching up after operation, of signal S. Then, when magnet I9 is reenergized, armature 20 is attracted to its position wherein armature I3 is engaged by pawl 22 and is held at its latched position, and the armature 2! is shifted to its extreme right-hand position by virtue of the weight of the armature I3 and arm ill to open contact 2324 and thereby terminate the operation of signal S.

The reference character T designates a transformer provided with secondary windings 25 and 26, and with a primary winding 21 connected with a suitable source of alternating current, such as a generator not shown.

The reference character 28 designates a full wave rectifier having its input terminals 29 and 30 constantly connected across the terminals of secondary winding 25 of transformer T, and provided with output terminals 3| and 32.

The reference character B designates a suitable stand-by source of current, herein shown as a battery.

The reference character PTR. designates a power transfer relay which serves, as will be explained hereinafter, to transfer the operation of signal S from its normal source of current to the stand-by source of current in the event the voltage of the normal source drops below a predetermined level. The relay PTR is connected across output terminals of rectifier 28 the circuit passing from terminal 3| of rectifier 28 through two branch circuit paths to the operating winding of the relay and to terminal 32 of the rectifier, a first circuit path of which serially includes front fiagman contact 5 of winding WI and front flagman contact 8 of winding W2, and the second circuit path of which serially includes front contact 33 of relay PTR. and a resister 34. It should be noted that the second path in the circuit for relay PTR includes its own front contact 33 and a resistor 34, and that the first path in the circuit for relay PTR includes front flagman contacts of windings WI and W2, but excludes the front contact 33 and resistor 34. It is apparent, therefore, that relay PTR may be energized and picked up only over its first circuit path, but that when once picked up it may be held up over its second circuit path wherein the resistor 34 decreases the energy level of the relay.

The operating element of mechanism M for signal S is provided with an energizing circuit usually passing from output terminal 3| of its normal source of current, rectifier 28, through front contact 33 of relay PTR, magnet I4 or I5 of the mechanism M in multiple with the winding of a bell 35 of the mechanism, contact 2423, and front contact 36 of relay PTR to the other terminal 32 of the rectifier. Whenever relay PTR is released, however, the operating element of signal S is connected across the stand-by source, the circuit in that event passing from one terminal of battery B through back contact 3? of relay PTR,, magnet I4 or I5 of the mechanism M in multiple with the Winding of bell 35, contact 2423, and back contact 38 of relay PTR to the other terminal of battery B. The lamp L provided for signal arm I0 is usually connected across the secondary winding 26 of transformer T over a circuit passing from one terminal of winding 26 through front contact 39 of relay PTR, back contact 4 of winding WI or back contact I of winding W2, the filament of lamp L, and front contact 40 of relay PTR to the other terminal of secondary winding 26 of transformer T. Whenever relay PTR is released, however, the lamp L is connected across the stand-by source of current, battery B, the circuit passing from one terminal of battery B through back contact 4i of relay PTR,, back contact 4 of winding WI or back contact I of winding W2, the filament of lamp L, and back contact 42 of relay PTR to the other terminal of battery 13.

The latching magnet I9 of signal mechanism M is normally energized over a circuit passing from. one terminal of battery B through front flagman contact 6 of winding WI, front flagman contact 9 of winding W2, and the operating winding of magnet I9 to the other terminal of battery B.

Normally, the apparatus is in the condition illustrated in the drawing. In this condition of the apparatus, no train is operating upon section D-E or E-F so that windings WI and W2 of relay XR are energized, relay PTR is connected across the output terminals of rectifier 28 over both its first and second circuit paths, the latching element for mechanism M is energized, and the operating element for mechanism M is deenergized.

In the event that a train enters section DE or E-F' in approaching the intersection, the winding WI or W2 associated with the track section so entered is released. In explaining the operation of the apparatus embodying my invention, I shall assume that section DE is entered by an eastbound train approaching the intersection with the result that winding WI releases to close back contact 4 and to open front flagman contacts 5 and 6. The opening of front contact 5 opens the first branch path provided in the circuit for relay PTR, the relay being retained energized over its second branch path, and the opening of front contact 6 of winding WI opens the circuit for latching magnet I9 of mechanism M, thereby releasing its armature 20 and closing contact 23-24 to establish the operating condition for signal S, which now operates from rectifier power in the manner described hereinbefore. The closing of back contact 4 of winding WI completes the circuit for lamp L of the signal arm, whereby the lamp displays a lighted indication to highway users.

In the event that the voltage of the normal source of supply for mechanism M remains above the value necessary to effect proper operation tion of its operation, relay PTR remains energized and signal S continues to operate from the rectifier power until such time as the train vacates section DE and winding WI picks up.

the signal arm of signal S are transferred to the battery stand-by power over circuits previously traced. The operating element of signal S and lamp L continue to operate from the battery power until such time as the train vacates section D-E and winding WI picks up. When winding Wl picks up, the operation'of signal S and lamp L is terminated, the signal arm being latched to its obscured'position, and the first circuit for relay PTR is completed, whereby if rectifier 28 is energized, relay PTR picksup to restore the apparatus to'its normal condition.

It should be noted that lamp L for the signal arm if], being connected across secondary winding 26 of transformer T, is normally independent of the operation of rectifier 28. Similarly, the latching magnet I9 is connected across the standby source B, whereby the current supplied to such magnet is not interrupted in the event that the power output of rectifier 28 varies so that relay P'I'R. releases or picks up. It should further be noted that relay PTR. is so controlled that, when signal S is controlled to its operating condition and relay PTR once becomes released due to a low voltage output of rectifier 28, the relay is not picked up to transfer the operation of signal S to rectifier power until the operation of the signal is terminated and the signal is latched up when the train clears the intersection. It can be seen, therefore, in the event that the ouput volage of rectifier 28 is critical, a pumping action, that is, alternate picking up and releasing of the relay armature does not result once the relay PTR is released.

Although I have, herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be'made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I.

gizing said power transfer relay from said first source of current including a front Contact of said power transfer relay and a resistor whereby when said track relay is released there willbe established in said power transfer relay an energy level effective to maintain its armature picked up provided the voltage applied to its windings exceeds the operating voltage of said signal, circuit means controlled by said track relay and said power transfer relay for energizing said signal from said first source of current when and only when said track relay is released and said power transfer relay is picked up, a second source of current, and other circuit meanscontrolled by said track relay and bysaid power transfer relay for energizing said signal from said second source of current when and only when said track relay is released and said power transfer relay also is released.

. 2. In combination, a stretch of railway track intersected by a highway and divided into a track section provided with a track circuit including a track relay, a highway crossing signal located at such intersection comprising an operating element which requiresa given operating voltage for operation and a; signal lamp, a source of alternating currentQa rectifier for rectifying said alternating current, a power transfer relay normally energized over apick-up circuit controlled by said track relay and receiving energy from the output terminals of said rectifier, stick circuit means for said power transfer relay receiving energy from the output terminals of said rectifier and including a resistor whereby when said track relay is released said power transfer will be held energized if and only if the voltage received by the relay from said rectifier exceeds the operating voltage of said signal, means controlled by said track relay and by said power transfer relay and effective when said track relay is released and said power transfer relay is picked up for energizing said signal lamp from said source of alternating current, other means controlled by said track relay and by said power transfer relay and effective when said track relay is released and said power transfer relay is picked up for energizing said operating element from said rectifier, a second source of current, and means controlled by said track relay and by said power transfer relay and effective when said track relay and said power transfer relay are both released for energizing said signal lamp and said operating element from said second source of current.

3. In combination, a stretch of railway track intersected by a highway and a track section having a track relay, a highway crossing signal located at such intersection comprising a nor,- mally deenergized operating element which requires a given operating voltage for operation and a normally energized latching element, a first source of current, a power transfer relay normally energized from said first source of current over a pick-up circuit controlled by said'track relay, a stick circuit for energizing said power transfer relay from said first source of current and including a resistor whereby when said track relay is released the armature of said power transfer relay is maintained in its picked up condition only when the voltage applied to its winding is equal to or exceeds the operating voltage of the operating element of said signal, circuit means controlled by said track relay and by said power transfer relay and effective when said track relay is released and said power transfer relay is picked up for energizing the operating element of said signal from said first source of current, a second source of current, circuit means controlled by said track relay for normally energizing the latching element of said signal from said second source of current, and circuit means controlled jointly by said track relay and by said power transfer relay and effective when said track relay and said power transfer relay are both released for energizing the operating element of said signal from said second source of current.

4. In combination with a section of railway track having a track relay responsive to trafiio 1| conditions in the section, a signal which requires a given operating voltage for operation, two sources of current one of which is a normal source and the other of which is a stand-by source, a normally energized power transfer relay, a pickup circuit for said power transfer relay receiving energy from said normal source and controlled by said track relay, a stick circuit for said power transfer relay also receiving energy from said normal source and including a resistor whereby when said signal is caused to operate said power transfer relay is maintained picked up only if the voltage received by the relay from the normal source exceeds the operating voltage of said signal, and means controlled by said power transfer relay for conditioning said signal for operation from onelor the other of said two sources of current.

5. The combination with a section of railway track having a track relay responsive to traffic conditions in the section for controlling the operation of a signal which requires a given operating voltage for operation, the signal usually being-operated from a normal source of current but being operated from a stand-by source of current in the event of a failure of power from the normal source, of a normally energized power transfer relay, a pick-up circuit for said power transfer relay controlled by the track relay and receiving energy from the normal source of current, a stick circuit for said power transfer relay also receiving energy from the normal source of current and including a resistor whereby when the signal is operating said power transfer relay is maintained picked up only if the voltage received by the relay from the normal source exceeds the operating voltage of the signal, and means controlled by said power transfer relay for conditioning the signal for operation from the normal or from the stand-by source of current.

PAUL H. CRAGO.

CERTIFICATE OF CORRECTION. Patent No. 2,18 6,800. Januarj 9, 19L1O.

PAUE H. CRAGO It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows; Page 5, second column, line b5, claim 5, after the word "and" insert provided with;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of March, A. D. 19110.

Henry Van Arsdale,

(Seal) Acting Commissioner of Patents. 

